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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "ScriptLoadRequest.h"
#include "ScriptLoader.h"
#include "mozilla/PerfStats.h"
#include "mozilla/Preferences.h"
#include "mozilla/ProfilerMarkers.h"
#include "mozilla/ScopeExit.h"
#include "mozilla/StaticPrefs_browser.h"
#include "mozilla/Vector.h"
#include "zlib.h"
using namespace mozilla;
namespace JS::loader {
#undef LOG
#define LOG(args) \
MOZ_LOG(mozilla::dom::ScriptLoader::gScriptLoaderLog, \
mozilla::LogLevel::Debug, args)
/*
* ScriptBytecodeDataLayout
*
* ScriptBytecodeDataLayout provides accessors to maintain the correct data
* layout of the ScriptLoadRequest's script bytecode buffer.
*/
class ScriptBytecodeDataLayout {
public:
explicit ScriptBytecodeDataLayout(mozilla::Vector<uint8_t>& aBytecode,
size_t aBytecodeOffset)
: mBytecode(aBytecode), mBytecodeOffset(aBytecodeOffset) {}
uint8_t* prelude() const { return mBytecode.begin(); }
size_t preludeLength() const { return mBytecodeOffset; }
uint8_t* bytecode() const { return prelude() + mBytecodeOffset; }
size_t bytecodeLength() const { return mBytecode.length() - preludeLength(); }
mozilla::Vector<uint8_t>& mBytecode;
size_t mBytecodeOffset;
};
/*
* ScriptBytecodeCompressedDataLayout
*
* ScriptBytecodeCompressedDataLayout provides accessors to maintain the correct
* data layout of a compressed script bytecode buffer.
*/
class ScriptBytecodeCompressedDataLayout {
public:
using UncompressedLengthType = uint32_t;
explicit ScriptBytecodeCompressedDataLayout(
mozilla::Vector<uint8_t>& aBytecode, size_t aBytecodeOffset)
: mBytecode(aBytecode), mBytecodeOffset(aBytecodeOffset) {}
uint8_t* prelude() const { return mBytecode.begin(); }
size_t preludeLength() const { return mBytecodeOffset; }
uint8_t* uncompressedLength() const { return prelude() + mBytecodeOffset; }
size_t uncompressedLengthLength() const {
return sizeof(UncompressedLengthType);
}
uint8_t* bytecode() const {
return uncompressedLength() + uncompressedLengthLength();
}
size_t bytecodeLength() const {
return mBytecode.length() - uncompressedLengthLength() - preludeLength();
}
mozilla::Vector<uint8_t>& mBytecode;
size_t mBytecodeOffset;
};
bool ScriptBytecodeCompress(Vector<uint8_t>& aBytecodeBuf,
size_t aBytecodeOffset,
Vector<uint8_t>& aCompressedBytecodeBufOut) {
// TODO probably need to move this to a helper thread
AUTO_PROFILER_MARKER_UNTYPED("ScriptBytecodeCompress", JS, {});
PerfStats::AutoMetricRecording<PerfStats::Metric::JSBC_Compression>
autoRecording;
ScriptBytecodeDataLayout uncompressedLayout(aBytecodeBuf, aBytecodeOffset);
ScriptBytecodeCompressedDataLayout compressedLayout(
aCompressedBytecodeBufOut, uncompressedLayout.preludeLength());
ScriptBytecodeCompressedDataLayout::UncompressedLengthType
uncompressedLength = uncompressedLayout.bytecodeLength();
z_stream zstream{.next_in = uncompressedLayout.bytecode(),
.avail_in = uncompressedLength};
// Note: deflateInit needs to be called before deflateBound.
const uint32_t compressionLevel =
StaticPrefs::browser_cache_jsbc_compression_level();
if (deflateInit(&zstream, compressionLevel) != Z_OK) {
LOG(
("ScriptLoadRequest: Unable to initialize bytecode cache "
"compression."));
return false;
}
auto autoDestroy = MakeScopeExit([&]() { deflateEnd(&zstream); });
auto compressedLength = deflateBound(&zstream, uncompressedLength);
if (!aCompressedBytecodeBufOut.resizeUninitialized(
compressedLength + compressedLayout.preludeLength() +
compressedLayout.uncompressedLengthLength())) {
return false;
}
memcpy(compressedLayout.prelude(), uncompressedLayout.prelude(),
uncompressedLayout.preludeLength());
memcpy(compressedLayout.uncompressedLength(), &uncompressedLength,
sizeof(uncompressedLength));
zstream.next_out = compressedLayout.bytecode();
zstream.avail_out = compressedLength;
int ret = deflate(&zstream, Z_FINISH);
if (ret == Z_MEM_ERROR) {
return false;
}
MOZ_RELEASE_ASSERT(ret == Z_STREAM_END);
aCompressedBytecodeBufOut.shrinkTo(zstream.next_out -
aCompressedBytecodeBufOut.begin());
return true;
}
bool ScriptBytecodeDecompress(Vector<uint8_t>& aCompressedBytecodeBuf,
size_t aBytecodeOffset,
Vector<uint8_t>& aBytecodeBufOut) {
AUTO_PROFILER_MARKER_UNTYPED("ScriptBytecodeDecompress", JS, {});
PerfStats::AutoMetricRecording<PerfStats::Metric::JSBC_Decompression>
autoRecording;
ScriptBytecodeDataLayout uncompressedLayout(aBytecodeBufOut, aBytecodeOffset);
ScriptBytecodeCompressedDataLayout compressedLayout(
aCompressedBytecodeBuf, uncompressedLayout.preludeLength());
ScriptBytecodeCompressedDataLayout::UncompressedLengthType uncompressedLength;
memcpy(&uncompressedLength, compressedLayout.uncompressedLength(),
compressedLayout.uncompressedLengthLength());
if (!aBytecodeBufOut.resizeUninitialized(uncompressedLayout.preludeLength() +
uncompressedLength)) {
return false;
}
memcpy(uncompressedLayout.prelude(), compressedLayout.prelude(),
compressedLayout.preludeLength());
z_stream zstream{nullptr};
zstream.next_in = compressedLayout.bytecode();
zstream.avail_in = static_cast<uint32_t>(compressedLayout.bytecodeLength());
zstream.next_out = uncompressedLayout.bytecode();
zstream.avail_out = uncompressedLength;
if (inflateInit(&zstream) != Z_OK) {
LOG(("ScriptLoadRequest: inflateInit FAILED (%s)", zstream.msg));
return false;
}
auto autoDestroy = MakeScopeExit([&]() { inflateEnd(&zstream); });
int ret = inflate(&zstream, Z_NO_FLUSH);
bool ok = (ret == Z_OK || ret == Z_STREAM_END) && zstream.avail_in == 0;
if (!ok) {
LOG(("ScriptLoadReques: inflate FAILED (%s)", zstream.msg));
return false;
}
return true;
}
#undef LOG
} // namespace JS::loader
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